Intussusception is a common cause of small bowel obstruction in infancy and early childhood. As in other forms of intestinal obstruction, there is stagnation of enteral content and edema of the bowel wall, theoretically facilitating translocation of bacteria. Since 1987, 85 cases of intussusception have been at this institution, of which 24 underwent laparotomy. Twenty (83%) developed a fever of more than 38.0 degrees at a mean of 11 hours postoperatively, lasting for less than 24 hours. Of the 61 cases that were treated by barium enema (a success rate of 72%), a similar fever peak was recorded in 26 (43%). All but who patients were afebrile on admission, and all were afebrile upon discharge. Hospital stay was 1.8 days for non-operated patients two remained afebrile and 2.9 days for those who developed a transient fever (p less than 0.05). We postulate that this temporary rise in temperature following manipulation of intussuscepted bowel is caused by a transient bacteremia or endotoxinemia due to bacterial translocation through the intestinal wall, similar to the process that has been described in other forms of intestinal obstruction. Awareness of this phenomenon could avoid needless fever workups, thereby reducing costs and hospital stay. The concept of bacterial translocation casts a doubt on the infectious theory of idiopathic intussusception, since the presence of infected mesenteric lymph nodes could follow, rather than proceed the intussusception.